Buggy code:
public void ireturn ( ) { } public boolean isDefinitelyAssigned ( Scope scope , int initStateIndex , LocalVariableBinding local ) { } public void ishl ( ) { } public void ishr ( ) { } public void istore ( int iArg ) { } public void istore_0 ( ) { } public void istore_1 ( ) { } public void istore_2 ( ) { } public void istore_3 ( ) { } public void isub ( ) { } public void iushr ( ) { } public void ixor ( ) { } public final void jsr ( BranchLabel lbl ) { } public final void jsr_w ( BranchLabel lbl ) { } public void l2d ( ) { } public void l2f ( ) { } public void l2i ( ) { } public void ladd ( ) { } public void laload ( ) { } public void land ( ) { } public void lastore ( ) { } public void lcmp ( ) { } public void lconst_0 ( ) { } public void lconst_1 ( ) { } public void ldc ( float constant ) { } public void ldc ( int constant ) { } public void ldc ( String constant ) { } public void ldc ( TypeBinding typeBinding ) { } public void ldc2_w ( double constant ) { } public void ldc2_w ( long constant ) { } public void ldcForIndex ( int index , char [ ] constant ) { } public void ldiv ( ) { } public void lload ( int iArg ) { } public void lload_0 ( ) { } public void lload_1 ( ) { } public void lload_2 ( ) { } public void lload_3 ( ) { } public void lmul ( ) { } public void lneg ( ) { } public final void load ( LocalVariableBinding localBinding ) { } public final void load ( TypeBinding typeBinding , int resolvedPosition ) { } public void lookupswitch ( CaseLabel defaultLabel , int [ ] keys , int [ ] sortedIndexes , CaseLabel [ ] casesLabel ) { } public void lor ( ) { } public void lrem ( ) { } public void lreturn ( ) { } public void lshl ( ) { } public void lshr ( ) { } public void lstore ( int iArg ) { } public void lstore_0 ( ) { } public void lstore_1 ( ) { } public void lstore_2 ( ) { } public void lstore_3 ( ) { } public void lsub ( ) { } public void lushr ( ) { } public void lxor ( ) { } public void monitorenter ( ) { } public void monitorexit ( ) { } public void multianewarray ( TypeBinding typeBinding , int dimensions ) { } public void new_ ( TypeBinding typeBinding ) { } public void newarray ( int array_Type ) { } public void newArray ( ArrayBinding arrayBinding ) { } public void newJavaLangAssertionError ( ) { } public void newJavaLangError ( ) { } public void newJavaLangIllegalArgumentException ( ) { } public void newNoClassDefFoundError ( ) { } public void newStringContatenation ( ) { } public void newWrapperFor ( int typeID ) { } public void nop ( ) { } public void optimizeBranch ( int oldPosition , BranchLabel lbl ) { for ( int i = 0 ; i < ( this . countLabels ) ; i ++ ) { BranchLabel label = this . labels [ i ] ; if ( oldPosition == ( label . position ) ) { label . position = position ; if ( label instanceof CaseLabel ) { int offset = ( position ) - ( ( ( CaseLabel ) ( label ) ) . instructionPosition ) ; for ( int j = 0 ; j < ( label . forwardReferenceCount ) ; j ++ ) { int forwardPosition = label . forwardReferences [ j ] ; <START_BUG> this . writeSignedShort ( forwardPosition , offset ) ; <END_BUG> } } else { for ( int j = 0 ; j < ( label . forwardReferenceCount ) ; j ++ ) { final int forwardReference = label . forwardReferences [ j ] ; this . writePosition ( lbl , forwardReference ) ; } } } } } public void pop ( ) { } public void pop2 ( ) { } public void pushOnStack ( TypeBinding binding ) { } public void putfield ( FieldBinding fieldBinding ) { } public void putstatic ( FieldBinding fieldBinding ) { } public void record ( LocalVariableBinding local ) { } public void recordExpressionType ( TypeBinding typeBinding ) { } public void recordPositionsFrom ( int startPC , int sourcePos ) { } public void registerExceptionHandler ( ExceptionLabel anExceptionLabel ) { } public void removeNotDefinitelyAssignedVariables ( Scope scope , int initStateIndex ) { } public void reset ( AbstractMethodDeclaration referenceMethod , ClassFile targetClassFile ) { } public void resetForProblemClinit ( ClassFile targetClassFile ) { } private final void resizeByteArray ( ) { } public final void ret ( int index ) { } public void return_ ( ) { } public void saload ( ) { } public void sastore ( ) { } public void sendOperator ( int operatorConstant , int type_ID ) { } public void sipush ( int s ) { } public void store ( LocalVariableBinding localBinding , boolean valueRequired ) { } public void swap ( ) { } public void tableswitch ( CaseLabel defaultLabel , int low , int high , int [ ] keys , int [ ] sortedIndexes , CaseLabel [ ] casesLabel ) { } public void throwAnyException ( LocalVariableBinding anyExceptionVariable ) { } public String toString ( ) { } public void updateLastRecordedEndPC ( Scope scope , int pos ) { } protected void writePosition ( BranchLabel label ) { } protected void writePosition ( BranchLabel label , int forwardReference ) { }

Fix:
this . writeSignedWord ( forwardPosition , offset ) ;